Controlling generator



Feb. 7, 1933. c. MCNEIL 1,896,142

CONTROLLING GENERATOR Filed Jan. 16, 1929 a! 2D 8 Zfmaentor CittomegsPatented Feb. 7, 1933 UNITED STATES PATENT OFFICE CHARLES I. MCNEIL, OFBLOOMFIELD, NEW JERSEY, ASSIGNOR TO ECLIPSE MACHINE COMPANY, OF ELMIRA.HEIGHTS, NEW YORK, A CORPORATION OF NEW YORK CONTROLLING GENERATORApplication filed January 16, 1929. Serial No. 332,998. R E l S S U EThis invention relates to controlling or regulating the output of anelectric current generator.

It has heretofore been proposed to employ a regulator of the vibratingreed or armature type for controlling the output, such as the voltageoutput, of a generator. Regulators of this type embody a pair ofcontacts which are opened and closed by an electromagnet lo for purposeswell understood in the art, the

opening and closing movements of. the contacts being usually of theorder of to 4 0 cycles per second. When regulators of this type areemployed for controlling the voltage output of a generator used in radiotransmitting apparatus of the continuous-wave type the action of thecontacts results in an intermittent note in the receiver so similar inpitch to that of other sounds in the transmitted waves as to renderimpo$ible, in many instances, the satisfactory reception of signals.Accordingly, one of the objects of the present invention is to providenovel regulating means of the vibratory type which is so constituted asto overcome the above objectionable effect.

Another object of the invention is to provide a novel regulatorembodying a pair of coacting contacts for intermittently in-- terruptingan electric circuit and means for rendering the action of said contactsof relatively high frequency such, for example, as 80 to 300 or morecycles per second.

Another object is to provide a novel methed for controlling thefrequency of opening and closing of a pair of coa'cting contacts of thecharacter above indicated. For claims to this novel method reference isto be had to applican'ts co-pending application Serial 40 No. 618,783,filed June 22, 1932, the claims herein being directed only to certainforms of apparatus for carrying said novel method into efiect.

Another object is to provide a novel re ulator embodying anelectromagnet provi ed with a plurality of coils or windings of suchcharacter that the make-and-break action of the contacts is ofrelativelyhigh frequency.

A further object is to provide a regulator embodying a multi-coilelectromagnet, the

various coils being so formed and combined as to insure properregulation regardless of changes in speed of and load on the generator.

Another object is to provide a novel voltage regulator of the vibratingarmature ty 6 which is particularly adapted for use in re iotransmitting apparatus. The above and other objects will appear morefully hereafter in the detailed description.

Two embodiments of the invention are illustrated in the accompanyingdrawin s, but it is to be expressly understood that e drawings are forpurposes of illustration only and are not designed as a definition ofthe limits of the invention, reference being had for this purpose to theappended claims.

In the drawing:

Fig. 1 is a diagrammatical View tillustrating one form of regulatingapparatus embodying the present invention; and 7 Fig. 2 is adiagrammatical view of another embodiment of the invention.

Referring more particularly to Fi 1 the armature of the generator to beregu ated is indicated at 3, the field winding at 4, and 7 the fieldresistance at 5, said winding and resistance beingv connected in seriesacross the positive main 6 and the negative main 7.

The novel regulating means comprises a pair of contacts 8 and 9 whichare normally closed and are shunted around the resistance 5. Contact 9is mounted on a vibrating armature 10 which is pivotally mounted in anysuitable manner, and adjustable resilient means such as a coil spring 11is operatively connected to said armature to normally maintain contact 9in engagement with contact 8. An electromagnet having a core 12, whichis preferably laminated, is associated with armature 10, and spring 11is so adjusted that when the voltage of the generator rises above apredetermined value the electromagnet is effective to overcome thetension of said spring and move contact 9 out of enga ement with contact8, whereupon the field resistance 5 is placed in circuit with the field4. The resistance of the field circuit is now of such value as toprevent the desired amount of field current from flowing, whereupon areduction in the generator voltage is produced.

This dropping of the voltage weakens the magnetic field of theelectromagnet to such an extent that the contacts 8 and 9 are closed byspring 11 to short circuit resistance 5, whereupon the field flux andarmature voltage are again built up.

The core 12 of the electromagnet carries a winding 13 which is in serieswith a resistance 14, the winding and resistance being connected acrossthe mains 6 and 7 in parallel with contacts 8, 9. The magnetic field setup by parallel coil 13'rises or falls relatively slowly, since it variesin accordance with the changes in the voltage in the armature. Thelatter in turn follows the changes of current the field. Accordingly, inregulators embodying only a coil such as is indicated at 13 the openingand closing movements of contacts 8 and 9 are relatively slow,i. e.,they are of the order of 10 to 40 cycles per secon In accordance withthe present invention means are provided for speeding up the action ofthe contacts, whereby the movement of the same is of a high frequencyas, for example, 7 For this purpose 80 to 300 or more cycles per second.the core 12 carries a second winding 15 which is connected in serieswith a resistance 16, said winding and resistance being shunted aroundgenerator field 4 and in series with contacts 8 and 9. Coil 15 is woundin such a manner as to strengthen the magnetic field set up in core 12by the'coil 13, and the tension of-springll is overcome only when bothcoils coact to produce the desired strength of field.

When the contacts are closed current flows from the positive main 6through said contacts, series coil 15, and resistance 16, and saidseries coil coacts with parallel coil 13 to set up the magnetic field incore 12. When the voltage output of the generator exceeds apredetermined amount as determined by the setting of spring 11, themagnetic field of the electromagnet is sufiiciently strong, due to thecombined action of coils 13 and 15, to overcome the tension of spring 11and move contact 9 out of engagement with contact 8.

from the use of a single coil such as parallel The instant the contactsopen the current in series coil 15 fallsfihus producing a sudden drop inthe flux of core 12 and this drop is independent of the fall of thevoltage in the armature 3. Armature 10 instantly moves to reenga'gecontact 9 with contact 8, due to the action'of spring 11. A much quickeraction of the contacts is thus obtained than results coil 13 since themagnetic field produced by the latter falls relativey slowly inaccordance with the drop of voltage in the armature.

The use of series coil 15 in combination with parallel coil 13 issuflicient to raise the frequency of the contacts to as high as 80 to300 cycles or more per second. This change in the frequency of thecontacts may not entirely eliminate the intermittent note result- .ofthe regulator.

I value of the ing from the transmitted waves and hence will. notinterfere with the reception of the signals. In other words, theregulator of the present invention is so constructed as to eliminte orminimize the interference or noises in radio signals emitted by atransmitter energized by a voltage regulated generator.

The resistance units 14 and 16 may be employed asindicated in order topermit the use of a larger current flow in coils 13 and 15 withoutdanger of overheating the coils as might result from winding theresistances directly on core 12. The larger portion of the heat isgenerated in the resistance and by placing said resistance at a distancefrom the coil a greater flow of current may be used for a predeterminedcoil temperature. Since the circuit 15, 16 is of small inductance itacts to absorb a portion of the voltage set up in field 4 by the suddenchanges in field current.

It is highly desirably that the regulator maintain the voltage constantwithin very narrow limits. Since the current in series coil 15 varies inproportion to the field current, which latter in turn varies with thespeed of and the load on the generator, a change in the current flowingthrough said coil results in a slight change in the Conversely, ondecrease in the effective field current (such as results from anincrease in generator speed or a decrease in load) the voltage impressedupon coil 15 decreases, thereby weakening the magnetic pull. To offsetthis decrease in pul coil 13 must be strengthened by increase in voltagefrom the generator in order to efiect opening of contacts 8 and 9. Thusthere is a tendency for the generator voltage to rise with increase inspeed or removal of load. This tendency may be overcome, or at leastcompensated for by the use of the arrangesetting ment shown in Fig. 2,now to be described.

15 is ineffective to vary the regulator setting.

For this purpose the core 17 of the electromagnet carries a third coil18 in series with a resistance 19, said coil and resistance being inparallel with contacts 8 and 9 and also in series with coil 15. When thecontacts are open. the current flowing through coil 18 is relativelyhigh and the current flowing through coil 15 is relatively low, and thefield set up by coil 18 is acting in a direction opposite to that set upin coil 15. When the contacts are closed, substantially no current flowsthrough coil 18 while a relatively large amount of current flows throughcoil 15, and,

as pointed out above in connection with Fig. 1, the coils 15 and 13coact together to set up the desired magnetic field for opening contacts8 and 9.

As the voltage tends to rise above the desired amount, a point isreached where the field set up by coils 13 and 15 is effective toovercome the tension of spring 11 and open contacts 8 and 9. Immediatelythe field of coil 15 drops due to the decrease in current now flowingthrough this coil while a relatively large amount of current flowsthrough coil 18, and the field of the latter is effective to diminish ornullify the effect of the field in coils 13 and 15. In other words, themagnetic field for holding the contacts open is very quickly destroyedand spring 11 is now effective without any delay to again close 1 hecontacts. Hence the speed of the regulator is increased by the use ofcoil 18.

This increase is further accelerated as the speed of the generatorincreases, becausethe current in coil 18 varies as the voltage acrossthe contacts 8 and 9, which in turn varies inve'rsely with the speed ofthe generator. Hence, at high speeds, (or upon removal of load)demagnetizing force of coil 18 is increased thereby causing contacts toclose sooner than at low speeds or at relatively high loads.

From the foregoing it is apparent that the addition of the coil 18serves to increase the speed of contact operation and compensate for.any tendency in the system toward a variation in voltage across thelines 6'and 7,

* the ultimate result being an improvement in the quality of regulation.

There is thus provided a'nov'el regulator which is simple inconstruction and which may be satisfactorily employed in radiotransmitting apparatus for maintaining constant voltage. It is to beexpressly understood, however, that the regulator is not limited in itsuse to the radio field, as will now be readily apparent to those skilledin the art,

and reference will be had to claims for a definition of the invention.

What is claimed is:

1. In combination with a generator having a field winding and a fieldresistance, means for regulatingthe voltage output of said generator byintermittently placing said the appended limits of the resistance incircuit with said field windingincluding a, pair of coacting'contacts,and means. including an electromagnet for controlling the enga ement ofsaid contacts, the electromagnet em odying a coil in series with saidcontacts and in parallel with said winding and another coil in parallelwith said contacts.

I 2.111 a regulator'of the type embodying a pair of eoactin Contacts, apivoted armature carrying one 0 said contacts, yielding means formaintaining said contacts closed, and an electromagnet for opening saidcontacts, the

electromagnet including a core and a plurality of coils wound thereon,one of the latter being in series with said contacts and another of thesame being in parallel with the contacts but in series with the firstnamed coil, andathird coil in parallel with the first.

3. In a regulator of the type having a vibrating armature, anelectromagnet comprising a core, a coil on-said core having a seriesrelationship with said armature and two other coils on said core, theseries coil being adapted to coact with one of said other coils to setup a predetermined field in said core and being adapted to coact withthe third coil to compensate for changes in the field induced by saidthird coil.

4. In a regulator of the vibrating armature type, an electromagnetcomprising a core, and a plurality of coils wound thereon, the first andsecond of said coils being adapted to coact one with the other to set upa predetermined field in said core, and a third coil adapted to coactwith said first and second coils, and the first named coil being alsoadapted to compensate for the changes in the magnetic field resultingfrom said third coil.

In testimony whereof I have signed this

